广州化学2004年第29卷1～4期总目次

带羧基丙烯酸酯乳液与无机粉料共混物的性能研究.................周一琨,李业琛,杨元龙,徐宇亮,葛家良PAA模板体系中CuS纳米棒的自组装合成...............................................刘成峰,翁家宝,郑雪琳,孙萃玉铁卟啉的合成及其电催化性能研究............................................................刘东任,蒋金芝,唐有根,汤一婕Cu2+/TiO2对甲基橙的光催化降解机理........................................张胜利,陈小明,罗和安,曾金祥,黄一姣掺Tb3+聚醋酸乙烯乳液的制备及性质研究.................................…     

特殊型纳米多孔阳极氧化铝模板的制备

多孔阳极氧化铝(PAA)模板具有六角有序排列的柱形孔,且孔径均匀可调,加之其良好的机械和热稳定性,在纳米材料领域得到了广泛研究和应用。近年来,人们通过改变铝阳极氧化条件制备出了多种特殊型纳米PAA模板,并利用这些模板结合物理或化学方法成功地合成了多种新型纳米功能材料。本文在简要介绍常规纳米PAA模板制备的基础上,较全面地综述了诸如孔道呈分叉形、锯齿形、骨形、倒圆锥形,孔洞呈菱形、三角形、正方形,孔道或孔壁结构呈周期性变化等特殊型纳米PAA模板的制备,揭示了电场强度和电解液种类、温度在PAA孔洞形貌尺寸调控方面的重要性,并展望了这类模板的发展方向及应用前景。     

水热模板法合成碲化镍纳米棒

研究了一种简单的碲化镍纳米棒的合成方法．在合成过程中,以碲纳米棒为反应模板,使之与新鲜生成的纳米镍颗粒反应生成碲化镍．利用X射线粉末衍射仪、扫描电子显微镜对产物进行了表征,研究了反应物中Ni和Te的摩尔比及反应温度对产物的影响,讨论了由Te纳米棒向NiTe纳米棒转化的机理．     

具有核壳结构的ZnO纳米棒@Ni-Co双氢氧化物复合物纳米片阵列的制备及其电化学性能

通过两步水热合成法制备了具有核壳结构的ZnO纳米棒@Ni-Co双氢氧化物复合材料纳米片阵列.首先,以碳布为基底,水热法生成的ZnO沉积在碳布上形成ZnO纳米棒花簇.其次,以ZnO纳米棒为模板,水热法生成的Ni-Co双氢氧化物纳米片沉积在ZnO纳米棒表面,形成ZnO纳米棒@Ni-Co双氢氧化物纳米片复合材料阵列.形貌、结构分析和电化学性能测试表明,以碳布为基底,成功地合成了以ZnO纳米棒为模板并具有核壳结构的ZnO纳米棒@Ni-Co双氢氧化物复合材料纳米片阵列,该复合材料纳米片阵列具有较大的纵横比,且分散均匀.合成的ZnO纳米棒@Ni-Co双氢氧化物复合材料纳米片阵列具有良好的电化学性能,当电流密度为1 A/g时,其比电容值可达531.6 F/g,该复合材料在超级电容器电极材料领域具有良好的应用前景.     

模板法室温合成CdS纳米棒

模板法室温合成CdS纳米棒;模板法;硫化镉;一维CdS纳米材料     

水热合成CdS纳米晶体的形貌控制研究

研究了水热合成CdS纳米晶体形貌的化学控制，选择不同的络合试剂为模板,研究其对水热合成CdS纳米晶体形貌的影响.实验发现若以络合试剂乙二胺、甲胺为模板时，产品CdS晶体的形貌分别为（20～30） nm×（200～600） nm和（40～50） nm×（200～600） nm尺寸的纳米棒;而以络合试剂吡啶、 氨为模板时，产品CdS晶体的形貌分别为平均尺寸约30 nm和20 nm的纳米颗粒.用XRD、TEM、XPS、PL和Raman光谱等技术对所得CdS纳米棒进行了表征.同时对水热合成CdS纳米晶体形貌的模板控制机制进行了探讨，提出了一种水热合成CdS纳米棒的络合物结构诱导生长机理.     

一种阿霉素/NO供体光敏纳米复合物的合成与性质研究

以硫化铜纳米晶(CuS-NCs)为核心,聚N-异丙基丙烯酰胺接枝壳聚糖(PNIPAM-g-CS)微粒为壳合成一种新型光敏纳米复合材料.在温度的调节下,N-异丙基丙烯酰胺(NIPAM)包覆CuS纳米晶,并接枝壳聚糖(CS),合成CuS杂PNIPAM-g-CS纳米复合材料.CuS在近红外光(980 nm)照射下具有光热效应,导致纳米复合物中PNIPAM-g-CS微粒受热体积收缩.负载阿霉素,这种纳米复合物就可作为光热诱导释放阿霉素的多功能纳米载体.再负载NO光敏供体(RBS),就可制备出阿霉素/RBS双负载的CuS杂PNIPAM-g-CS纳米载体.在可见光(365 nm)照射下,RBS光解释放NO.近红外光和可见光分别触发纳米载体释放阿霉素和NO,加上CuS纳米晶的光热效应,这种纳米载体可实现光触发双药物释放协同光热化疗杀伤肿瘤细胞.     

金纳米棒的制备、生长机理及纯化

金纳米棒由于其独特物理性质而在众多的各向异性金纳米颗粒中赢得了关注。目前,金纳米棒在纳米电子学、光学、生物医药等研究领域均具有良好的应用前景。对金纳米棒合成的有效调控直接决定着其形状、尺寸和长径比,而这些又进一步影响着金纳米棒的物理性质。本文梳理了金纳米棒制备方法的发展脉络,以模板法、电化学方法、种子生长法以及近年来出现的无种子生长法为主线,系统综述了金纳米棒制备过程实验参数调控对产物结构、物理性质的影响,详细阐述了关于单晶以及孪晶金纳米棒的生长机理,并介绍了提高产物纯度的分离纯化手段。     

单分散磷酸镧纳米棒的可控制备

采用一步水热法在无模板情况下合成了单一形貌和尺寸均匀的磷酸镧纳米棒,产物分散性好.这种合成方法操作简单、能耗低、合成条件可控,并且重复性很好、可大面积合成.用X射线粉末衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)对磷酸镧的形貌、结构以及相组成进行了分析.结果表明:所合成磷酸镧为单斜相独居石结构;纳米棒直径为15 nm,长度约为几百纳米,具有相当高的纵横比,有望在性能方面得到优化;磷酸镧纳米棒为单晶.对影响磷酸镧纳米棒形成的反应条件如水热温度和水热时间进行了研究,并详细研究了其生长过程.提出了磷酸镧纳米棒的可能生长机制是基于纳米颗粒的定向粘附作用.     

草酸沉淀法合成自组装纳米Co_3O_4及性质

<正>一维纳米材料具有高比表面积,表现出很多奇特的物理和化学性能,因此一维纳米材料的合成和性质引起了人们的广泛关注。目前,合成一维纳米氧化物的方法很多,如模板法合成一维纳米铁氧体、水热法合成γ-MnOOH纳米棒、静电纺丝法合     

硫化铜纳米棒的低热固相合成及其光学性能

在表面活性剂PEG-400存在的条件下,以醋酸铜和硫代乙酰胺为原料,利用低热固相化学反应,一步制备出分散均匀的硫化铜纳米棒.X射线粉末衍射和能量散射X射线能谱分析证明,产物为纯六角相的硫化铜.透射电镜和扫描电镜形貌分析表明,产物为棒状,直径为80～100nm,长度为200～500nm.紫外-可见光谱和光致发光光谱表明,硫化铜纳米棒的紫外和荧光最大吸收和发射波长与常规硫化铜相比均发生了明显的蓝移,表明所制备的硫化铜纳米棒具有良好的光学性质.     

Biomolecule-Assisted, Environmentally Friendly, One-Pot Synthesis of CuS/Reduced Graphene Oxide Nanocomposites with Enhanced Photocatalytic Performance

In this work, we develop a novel environmentally friendly strategy toward one-pot synthesis of CuS nanoparticle-decorated reduced graphene oxide (CuS/rGO) nanocomposites with the use of l-cysteine, an amino acid, as a reducing agent, sulfur donor, and linker to anchor CuS nanoparticles onto the surface of rGO sheets. Upon visible light illumination (λ > 400 nm), the CuS/rGO nanocomposites show pronounced enhanced photocurrent response and improved photocatalytic activity in the degradation of methylene blue (MB) compared to pure CuS. This could be attributed to the efficient charge transport of rGO sheets and hence reduced recombination rate of excited carriers.     

Synthesis of CeO2 nanorods via ultrasonication assisted by polyethylene glycol

Polycrystalline CeO2 nanorods 5-10 nm in diameter and 50-150 nm in length were synthesized via ultrasonication using polyethylene glycol (PEG) as a structure-directing agent at room temperature. The properties of the CeO2 nanorods were characterized by TEM, EDS, XRD, XPS, FT-IR, TG, BET, and UV-vis spectroscopy. Various reaction parameters, such as the content of PEG, the molecular weight of PEG, the concentration of KOH, the pH value, and the sonication time, were investigated by a series of control experiments. The content of PEG, the molecular weight of PEG, and the sonication time were confirmed to be the crucial factors determining the formation of one-dimensional CeO2 nanorods. A possible ultrasonic formation mechanism has been suggested to explain the formation of CeO2 nanorods.     

Tandem synthesis of silver nanoparticles and nanorods in the presence of poly(oxyethylene)-amidoacid template

Sequential formation of silver nanoparticles (AgNPs) and nanorods from the reduction of AgNO₃ was affected by a poly(oxyethylene)-amidoacid (POE-amidoacid) in aqueous solution. The requisite POE-amidoacid, consisting of –(CH₂CH₂O)_n– segments with amide and carboxyl groups, was simply prepared via amidation with trimellitic anhydride of a poly(oxyethylene)-monoamine (POE-amine) of molecular weight (M_w) ∼2000 g/mol. The POE-amidoacid afforded AgNPs as small as 5 nm in diameter, which gradually (over a period of months) self-assembled into nanorods that were 10–15 nm in width and 30–50 nm in length. The hierarchical formation of Ag species occurred only at ambient temperature, but Ag aggregates formed above 50 °C. The process could be monitored by UV absorption at 420 and 380 nm for AgNPs and nanorods, respectively, and by transmission electron microscopy (TEM) for the nanorods. Fourier transform infrared (FTIR) and tapping-mode atomic force microscopy (TM-AFM) analyses revealed that the structurally tailored POE-amidoacid was indeed multifunctional: it reduced Ag⁺, stabilized the obtained Ag⁰ species, and served as a template for the tandem formation of AgNPs and nanorods.     

Facile One‐Pot Synthesis of Tellurium Nanorods as Antioxidant and Anticancer Agents

Nanorods have been utilized in targeted therapy, controlled release, molecular diagnosis, and molecule imaging owing to their large surface area and optical, magnetic, electronic, and structural properties. However, low stability and complex synthetic methods have substantially limited the application of tellurium nanorods for use as antioxidant and anticancer agents. Herein, a facile one‐pot synthesis of functionalized tellurium nanorods (PTNRs) by using a hydrothermal synthetic system with a polysaccharide–protein complex (PTR), which was extracted from Pleurotus tuber‐regium, as a capping agent is described. PTNRs remained stable in water and in phosphate‐buffered saline and exhibited high hemocompatibility. Interestingly, these nanorods possessed strong antioxidant activity for scavenging 2,2′‐azinobis‐(3‐ethylbenzothiazoline‐6‐sulfonic acid radical cation (ABTS^.+) and 2,2‐diphenyl‐1‐picrylhydrazylhydrate (DPPH) free radicals and demonstrated novel anticancer activities. However, these nanorods exhibited low cytotoxicity toward normal human cells. In addition, the PTNRs effectively induced a decrease in the mitochondrial membrane potential in a dose‐dependent manner, which indicated that mitochondrial dysfunction might play an important role in PTNR‐induced apoptosis. Therefore, this study provides a one‐pot strategy for the facile synthesis of tellurium nanorods with novel antioxidant and anticancer application potentials.     

阴离子表面活性剂作为添加剂种子生长法制备尺寸可调的单分散金纳米棒

以不同阴离子表面活性剂作为添加剂种子生长法制备金纳米棒, 并考察阴离子表面活性剂种类对金纳米棒形貌及光学性质的影响。在十二烷基苯基磺酸钠(SDBS)存在下, 金纳米棒的产率明显高于使用十二烷基磺酸钠的反应体系。对添加SDBS的种子生长法制备金纳米棒的反应条件进行优化, 得到十六烷基三甲基溴化铵、SDBS、抗坏血酸和硝酸银的最佳浓度分别为0.04 mol·L^-1、2.4 mmol·L^-1、1.2 mmol·L^-1和0.08 mmol·L^-1。在此条件下, 金纳米棒的生长在30 min内完成, 所制备的金纳米棒表面等离子共振吸收峰位于823 nm, 其横纵比为(5±0.03)。当改变生长液中硝酸银浓度时, 金纳米棒的尺寸也随之发生改变。此外, 我们还探讨了SDBS的作用机理。相对于经典种子生长法, 新方法制备纳米金棒在尺寸可调性、单分散性和生物毒性方面明显改善, 可广泛应用于各种光学及生物分析。     

H2S Dosimetry by CuO: Towards Stable Sensors by Unravelling the Underlying Solid-State Chemistry

The precise detection of the toxic gas H₂S requires reliable sensitivity and specificity of sensors even at minute concentrations of as low as 10 ppm, the value corresponding to typical exposure limits. CuO can be used for H₂S dosimetry, based on the formation of conductive CuS and the concomitant significant increase in conductance. In theory, at elevated temperature the reaction is reversed and CuO is formed, ideally enabling repeated and long-term use of one sensor. Yet, the performance of CuO tends to drop upon cycling. Utilizing defined CuO nanorods we thoroughly elucidated the associated detrimental chemical changes directly on the sensors, by Raman and electron microscopy analysis of each step during sensing (CuO→CuS) and regeneration (CuS→CuO) cycles. We find the decrease in the sensing performance is mainly caused by the irreversible formation of CuSO₄ during regeneration. The findings allowed us to develop strategies to reduce CuSO₄ formation and thus to substantially maintain the sensing stability even for repeated cycles. We achieved CuO-based dosimeters possessing a response time of a few minutes only, even for 10 ppm H₂S, and prolonged life-time.     

Rapid synthesis of gold nanorods using a one-step photochemical strategy

Rapid synthesis of gold nanorods of controlled dimensions is one of the desired aspects of nanotechnology as a result of the potential of these nanomaterials for biomedical applications. The synthesis of gold nanorods has been achieved using a photoinitiator as an instant source of ketyl radicals, which allows the synthesis of gold nanorods in minutes. This is the first report providing a one-step synthesis of nanorods of controlled dimensions in 20-30 min using photoinitiator I-2959 as a source of ketyl radicals. Furthermore, the role of UV intensity, the concentration of silver ions, and the presence of cosolvents and a cosurfactant have been studied in detail in an effort to produce nanorods with controlled dimensions in higher yields. The role of acetone in nanorod synthesis has been explored in detail, and it has been demonstrated that, for the photochemical synthesis of nanorods using a photoinitiator, acetone is not a critical component and can be replaced by other water-miscible solvents, thus the successful synthesis of nanorods in tetrahydrofuran (THF) has been demonstrated. It has also been found that a cosurfactant and an organic solvent are not required for the synthesis of nanorods; however, their presence is found to improve the monodispersity of nanorod samples, in addition to providing a higher yield.     

Immobilization of gold nanorods onto acid-terminated self-assembled monolayers via electrostatic interactions

We report the immobilization of gold nanorods onto self-assembled monolayers (SAMs) of 16-mercaptohexadecanoic acid (16-MHA). The simple two step protocol involves formation of a SAM of 16-MHA molecules onto gold-coated glass slides and subsequent immersion of these slides into the gold nanorod solution. The nanorods, formed by a seed-mediated, surfactant-assisted synthesis protocol, are stabilized in solution due to surface modification by the surfactant cetyltrimethylammonium bromide (CTAB). Attractive electrostatic interactions between the carboxylic acid group on the SAM and the positively charged CTAB molecules are likely responsible for the nanorod immobilization. UV-vis spectroscopy has been used to follow the kinetics of the nanorod immobilization. The nature of interaction between the gold nanorods and the 16-MHA SAM has been probed by Fourier transform infrared spectroscopy (FTIR). The surface morphology of the immobilized rods is studied by scanning electron microscopy (SEM) and atomic force microscopy (AFM) measurements. SEM was also used to determine the density of the immobilized nanorods as a function of the pH of immobilization. Control over the surface coverage of the immobilized gold nanorods has been demonstrated by simple pH variation. Such well-dispersed immobilized gold nanorods with control over the surface coverage could be interesting substrates for applications such as surface-enhanced Raman spectroscopy (SERS).     

阴离子表面活性剂作为添加剂种子生长法制备尺寸可调的单分散金纳米棒

以不同阴离子表面活性剂作为添加剂种子生长法制备金纳米棒,并考察阴离子表面活性剂种类对金纳米棒形貌及光学性质的影响。在十二烷基苯基磺酸钠(SDBS)存在下,金纳米棒的产率明显高于使用十二烷基磺酸钠的反应体系。对添加SDBS的种子生长法制备金纳米棒的反应条件进行优化,得到十六烷基三甲基溴化铵、SDBS、抗坏血酸和硝酸银的最佳浓度分别为0.04 mol.L-1、2.4 mmol.L-1、1.2 mmol.L-1和0.08 mmol.L-1。在此条件下,金纳米棒的生长在30 min内完成,所制备的金纳米棒表面等离子共振吸收峰位于823 nm,其横纵比为(5±0.03)。当改变生长液中硝酸银浓度时,金纳米棒的尺寸也随之发生改变。此外,我们还探讨了SDBS的作用机理。相对于经典种子生长法,新方法制备纳米金棒在尺寸可调性、单分散性和生物毒性方面明显改善,可广泛应用于各种光学及生物分析。